The invention relates to apparatus for feeding disk-like objects at a fast, uniform rate, and is more particularly directed to improvements in means for preventing jamming of disk-like objects in such apparatus.
In U.S. Pat. No. 4,006,812, assigned to the assignee of the present invention, an automatic feeding hopper is disclosed for feeding disk-like objects such as shells or crowns for bottles at speeds up to and in excess of 4,000 pieces per minute. This equipment has the capability to maintain a flow of crowns through the hopper equal to the demands upon it, such as the demands imposed by a seal liner machine which molds seal liners of plastic material within crowns.
In the automatic feeding hopper of the aforementioned patent, a reservoir is provided which is dimensioned to receive a plurality of substantially horizontal rows of disk-like objects in a substantially vertical plane. A conveyor adjoins the reservoir for engagment with the substantial portion of the lowermost row of objects in the reservoir and for removing the disk-like objects from the reservoir for delivery in a single row into a vertically oriented supply chute. A deflecting or guide member having an upper concavely curved surface is intersected by a lower curved surface leading into a side of the exit chute, and the surface meet at an edge or joint located a distance above the surface of the conveyor slightly more than the diameter of a disk-like object. A nozzle directs air under pressure to an area just above the point where the concavely curved surfaces meet so that jamming at this point will be prevented. The crowns above the crowns on the conveyor are circulated back into the reservoir by the blast of air, so that the recirculated crowns may be positioned directly on the conveyor.
It has been found that the use of compressed air causes substantial wear on the base plate of the hopper magazine or reservoir in the area adjoining the deflecting member, and it has been necessary to use a great amount of compressed air; a 1/4 inch line discharging air at 60-70 p.s.i. Such wear has necessitated replacement of the worn surface. Considering the cost of energy for providing the compressed air, the down-time to replace worn parts and the cost of the worn parts, it has been determined that it costs approximately $1,200 per year per hopper to use compressed air as the means to prevent jamming. Since more than 100 hoppers are being used, it will be apparent that the cost of using compressed air anti-jamming means is not inexpensive.
Various magnetic arrangements have been used as part of or in conjunction with hoppers or other feeding apparatus. Stover U.S. Pat. No. 3,065,841, Daniels 3,269,514 and 3,863,802, Matteling 3,338,372 and Barr 3,067,852 each disclose a rotatably mounted disk having circumferentially spaced magnetic elements for engaging and moving crowns or shells from one point to another. In Barr, the rotatable disk having the spaced magnetic elements acts upon improperly oriented crowns to remove them from a conveyor belt with the aid of a stripper plate.